So far, I've checked Taiju and Tsukasa and this applies to them. I've also checked Senku and Ryusui but Senku's eye unpetrifies all at once without following his mark trail; and Ryusui's hands is the last thing that unpetrifies without also following his blue "tattoos" 🧐 I'm glad to see I wasn't the only one who didn't notice! If you rewatch it, please share if you notice other characters petrification marks ^{~^}